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LOS ANGELES, June 10 (Xinhua) -- The Aquarius/SAC-D observatory, NASA's first ever satellite to study the saltiness of Earth's oceans, is in excellent health after its launch early Friday, initial telemetry reports showed.The observatory rocketed into space from Vandenberg Air Force Base in California atop a United Launch Alliance Delta II rocket at 7:20:13 a.m. PDT (10:20:13 a.m. EDT).Less than 57 minutes later, the observatory separated from the rocket's second stage and began activation procedures, establishing communications with ground controllers and unfurling its solar arrays, NASA's Jet Propulsion Laboratory (JPL) said.During the next 25 days, the Aquarius/SAC-D service platform will be tested and maneuvered into its final operational, near-polar orbit 408 miles (657 kilometers) above Earth. Science operations will begin after the observatory's instruments are checked out. This commissioning phase may last up to 65 days, JPL said.Aquarius will map the global open ocean once every seven days for at least three years with a resolution of 93 miles (150 kilometers). The maps will show how ocean surface salinity changes each month, season and year. Scientists expect to release preliminary salinity maps later this year."Aquarius is a critical component of our Earth sciences work, and part of the next generation of space-based instruments that will take our knowledge of our home planet to new heights," said NASA Deputy Administrator Lori Garver. "The innovative scientists and engineers who contributed to this mission are part of the talented team that will help America win the future and make a positive impact across the globe."Aquarius will measure salinity by sensing thermal microwave emissions from the water's surface with three microwave instruments called radiometers. When other environmental factors are equal, these emissions indicate the saltiness of surface water. A microwave radar scatterometer instrument will measure ocean waves that affect the precision of the salinity measurement.Because salinity levels in the open ocean vary by only about five parts per thousand, Aquarius will be able to detect changes as small as approximately two parts per 10,000, equivalent to about one-eighth of a teaspoon of salt in a gallon of water."Data from this mission will advance our understanding of the ocean and prediction of the global water cycle," said Michael Freilich, director of NASA's Earth Science Division in the Science Mission Directorate at agency headquarters in Washington. "This mission demonstrates the power of international collaboration and accurate spaceborne measurements for science and societal benefit. This would not be possible without the sustained cooperation of NASA, CONAE and our other partners."The Aquarius/SAC-D (Satellite de Aplicaciones Cientificas) observatory is a collaboration between NASA and Argentina's space agency, Comision Nacional de Actividades Espaciales (CONAE).Aquarius was built by NASA's JPL and the Goddard Space Flight Center in Greenbelt, Maryland. NASA's Launch Services Program at the Kennedy Space Center in Florida manages the launch.JPL will manage Aquarius through its commissioning phase and archive mission data. Goddard will manage Aquarius mission operations and process science data. CONAE is providing the SAC-D spacecraft, optical camera, thermal camera with Canada, microwave radiometer, sensors from various Argentine institutions and the mission operations center. France and Italy also are contributing instruments.

WASHINGTON, Aug. 31 (Xinhua) -- Astronomers using NASA's Chandra X-ray Observatory discovered the first pair of supermassive black holes in a spiral galaxy similar to the Milky Way, NASA announced Wednesday.Approximately 160 million light years from Earth, the pair is the nearest known such phenomenon.The black holes are located near the center of the spiral galaxy NGC 3393. Separated by only 490 light years, the black holes are likely the remnant of a merger of two galaxies of unequal mass a billion or more years ago.Both of the supermassive black holes are heavily obscured by dust and gas, which makes them difficult to observe in optical light. Because X-rays are more energetic, they can penetrate this obscuring material. Chandra's X-ray spectra show clear signatures of a pair of supermassive black holes."If this galaxy weren't so close, we'd have no chance of separating the two black holes the way we have," said Pepi Fabbiano of the Harvard-Smithsonian Center for Astrophysics, who led the study that appeared Wednesday in on-line issue of the journal Nature. "Since this galaxy was right under our noses by cosmic standards, it makes us wonder how many of these black hole pairs we've been missing."Previous observations in X-rays and at other wavelengths indicated that a single supermassive black hole existed in the center of NGC 3393. However, a long look by Chandra allowed the researchers to detect and separate the dual black holes. Both black holes are actively growing and emitting X-rays as gas falls towards them and becomes hotter.When two equal-sized spiral galaxies merge, astronomers think it should result in the formation of a black hole pair and a galaxy with a disrupted appearance and intense star formation. A well-known example is the pair of supermassive black holes in NGC 6240, which is located about 330 million light years from Earth.However, NGC 3393 is a well-organized spiral galaxy, and its central bulge is dominated by old stars. These are unusual properties for a galaxy containing a pair of black holes.

LOS ANGELES, June 24 (Xinhua) -- Near-Earth asteroid 2011 MD will whip past Earth on June 27, but will not pose any threat, NASA's Jet Propulsion Laboratory (JPL) said on Friday.The asteroid will pass only 12,000 kilometers (7,500 miles) above the Earth's surface at about 9:30 EDT, according to JPL in Pasadena, Los Angeles.This small asteroid, only 5-20 meters in diameter, is in a very Earth-like orbit about the Sun, but an orbital analysis indicates there is no chance it will actually strike Earth on Monday, JPL said.If a rocky asteroid the size of 2011 MD were to enter Earth's atmosphere, it would be expected to burn up high in the atmosphere and cause no damage to Earth's surface, said JPL.The accompanying diagram gives a view of the asteroid's trajectory from the general direction of the Sun. This view indicates that 2011 MD will reach its closest Earth approach point in extreme southern latitudes (in fact over the southern Atlantic Ocean), according to JPL. The incoming trajectory leg passes several thousand kilometers outside the geosynchronous ring of satellites and the outgoing leg passes well inside the ring, JPL said.For a brief time, it may be bright enough to be seen even with a modest-sized telescope.One would expect an object of this size to come this close to Earth about every six years on average.The asteroid was discovered by the LINEAR near-Earth object discovery team observing from Socorro, New Mexico.

BRUSSELS, May 31 (Xinhua) -- A deadly outbreak of E.coli linked to contaminated cucumbers is sending Europe on high alert, as death toll from the disease climbed to 16 till Tuesday.So far, 15 people have reportedly died and more than 300 were seriously ill from infections linked to tainted vegetables in Germany. Experts said the numbers are expected to increase in the coming week."We hope the number of cases will go down but we fear it will worsen," said Oliver Grieve, spokesperson with the University Medical Center Schleswig where most German victims are being treated.The German government has identified the pathogen as hemolytic-uremic syndrome (HUS), a serious complication of a type of E. coli known as Shiga toxin-producing E.coli (STEC). The bacteria could damage blood cells and kidneys, and hence cause deaths.A woman in her 50s was confirmed to be the first fatal victim out of Germany by a local hospital on Tuesday. Officials at the hospital in Boras, southwestern Sweden, said the woman, who had recently traveled to Germany, was admitted on May 29.Swedish health authorities already said on Sunday that 36 people, all linked to travel in northern Germany, had been confirmed to have infected with E.coli, whereas cases were also reported in France, the Netherlands, Denmark and Britain.It was the second food scare for European consumers this year. In January, highly toxic dioxin was found in eggs, poultry and pork products across Germany.

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